pinhole photo of Portland sundial

There's a pinhole camera photo of the Portland Oregon Union Station sundial at: http://web.pdx.edu/%7Eharveyt/C1.html

Re: pinhole photo of Portland sundial

Does anyone know if this indeed is a sundial, or just a time sculpture? The dial has only 12 hours around its circumference. Most dials have 24 hours around the perimeter, and although it is possible to design one with just 12 hours, they are rarely made this way. In such a dial, the gnomon